Poor visual quality of wallpaper when QT_SCALE_FACTOR > 1

[denysformiga]

Hi,
I'm using DAT Linux 1.0.1-lxqt with a 4k monitor and noticed a low quality of wallpaper after change the QT_SCALE_FACTOR to be bigger than 1 to have menu bar, icons, etc. appropriate to my monitor. Looks good now, but I noticed that the image quality of the wallpaper becomes much poorer after the change.

Before:
    

After:
     

How can I fix that?
Is anyone else facing the same problem?

[dat-linux]

Hi, I think the image is 1920p. Sorry there's not a larger one I can give you. You can change it to whatever image you want, just right click on the desktop -> Desktop Prefs -> Background.

In general, I guess rescaling the desktop also rescales the bg image and this creates artefacts in the raster. I'm not sure if it's possible to avoid just the bg from rescaling, I would imagine not. You can try using a vector based image.

[denysformiga]

I'm using 4k images, and I saw the same problem in this discussion here.
Unfortunately, I don't understand how to apply the patch (12d0efb) mentioned in the “Possible Solution”.

Can you help me?

[dat-linux]

Well, the fix was made in the pcmanfm-qt codebase, so you'd need to download and build it. The Lubuntu Jammy repos only have a previous stable version unfortunately, the newer version may be a part of 24.04 upgrade (which DAT Linux 2.0 will be based on). Note, installing a later version of pcmanfm could break stuff.

Alternatively, you could merge the patch from the latest branch back into the 0.17 branch, and then build/install that. If this is possible at all, as the patch may not be backwards compatible.

[denysformiga]

Thanks for explanation. Sadly, I'll live with that. Set some wallpaper with few details, maybe something like 8-bit, and move on.